National Institute of Radiological Sciences

Hamamatsu-Photonics K.k.

Shimadzu Corporation

Hitachi Chemical Company, Ltd.

Naoko Inadama

Hideo Murayama

Taiga Yamaya

Eiji Yoshida

Fumihiko Nishikido

Kengo Shibuya

Takaji Yamashita

Tomohide Omura

Kenshi Fukumitsu

Hiroyuki Ishibashi

Keishi Kitamura

Keiji Sumiya

Mitsuo Watanabe

Takahiro Moriya

A light receiver for detecting incident time is installed on the side of a radiation source of a scintillator (including a Cherenkov radiation emitter), and information (energy, incident time, an incident position, etc.) on radiation made incident into the scintillator is obtained by the output of the light receiver. It is, thereby, possible to identify an incident position and others of radiation into the scintillator at high accuracy.

Method for detecting radiation, device thereof, and positron emission tomography scanner

A three-dimensional position-sensitive radiation detector is provided which has a three-dimensional array of photodetectors disposed on the surface of a scintillator block and which is capable of three-dimensionally identifying the position of light emission at which radiation has been detected within the detector. The three-dimensional position-sensitive radiation detector includes: a scintillator block including a central portion which restricts the direction of diffusion of light so as to direct the light in three axial directions and which has an optically discontinuous region, and an outer portion which is disposed on the outside of the central portion and which does not restrict the direction of diffusion of light; and photodetectors disposed on at least two outer circumferential surfaces of the scintillator block. The detector identifies three-dimensionally the position of light emission, thereby preventing deterioration in position discrimination performance even when inner scintillator elements are smaller than the photodetectors.

Three-dimensional position-sensitive radiation detector and method of identifying radiation detected positions therein

This aims to provide a DOI type radiation detector in which scintillation crystals arranged two-dimensionally on a light receiving surface to form rectangular section groups in extending directions of the light receiving surface of a light receiving element are stacked up to make a three-dimensional arrangement and responses of the crystals that have detected radiation are made possible to identify at response positions on the light receiving surface, so that a three-dimensional radiation detection position can be obtained. In the DOI type radiation detector, scintillation crystals are right triangle poles extending upwards from the light receiving surface and the response positions on the light receiving surface are characterized. With this structure, DOI identification of a plurality of layers can be carried out by simply performing an Anger calculation of a light receiving element signal.

DOI type radiation detector

A positron emission tomography (PET) scanner is provided which uses information on the time-of-flight difference (TOF) between annihilation radiations for image reconstruction. The scanner has detection time correction information (memory) corresponding to information on coordinates in a radiation detection element (e.g., scintillator crystal), in the depth and lateral directions, at which an interaction has occurred between an annihilation radiation and the crystal. Reference is made to the detection time correction information, thereby providing information on time-of-flight difference with improved accuracy. As such, an improved signal to noise ratio and spatial resolution are provided for image reconstruction using time-of-flight (TOF) difference.

Positron emission tomography scanner and radiation detector

A depth of interaction detector with uniform pulse-height comprises a multi-layer scintillator obtained by coupling at least two scintillator cells on a plane and then stacking the planar coupled scintillator cells, in layers, up to at least two stages and a light-receiving element connected to the bottom face of each scintillator cell of this multi-layer scintillator, wherein the detector is provided with a means for discriminating the position of a scintillator cell, which receives radiant rays and emits light rays and a means for making, uniform, the quantity of the light emitted from each scintillator cell and received by the light-receiving element. The detector can provide precise detection information even when radiation is absorbed by and emitted from a scintillator layer positioned above the scintillator layer optically coupled to the light-receiving element, permits the production of a depth of interaction detector having a three-dimensional depth of interaction-detecting function and can provide the same total output signal, which is independent of the position or a specific scintillator cell practically emitting light if the radiation energy is identical.

Depth of interaction detector with uniform pulse-height

The radiation three-dimensional position detector of the present invention comprises a scintillator unit (), a light receiving element () and an operation section (). The scintillator unit is disposed on the light incident plane of the light receiving element, wherein the scintillator unit is comprised of four layers of scintillator arrays, each layer being composed of scintillator cells arrayed in 8 row &#x2212;8 column matrix. The scintillator cell produces scintillation light corresponding to the radiation absorbed thereby. The optical characteristic of a partition material for separating neighboring scintillator cells, which faces at least one same side face is different between a scintillator cell Cincluded in one scintillator array layer (k1-th layer) and a scintillator cell Cincluded in the other scintillator array layer (k2-th layer).

Radiation three-dimensional position detector

Growing community of inventors

Chiba, Japan

Naoko Inadama